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1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/etherdevice.h>
3#include <linux/if_macvlan.h>
4#include <linux/if_tap.h>
5#include <linux/if_vlan.h>
6#include <linux/interrupt.h>
7#include <linux/nsproxy.h>
8#include <linux/compat.h>
9#include <linux/if_tun.h>
10#include <linux/module.h>
11#include <linux/skbuff.h>
12#include <linux/cache.h>
13#include <linux/sched/signal.h>
14#include <linux/types.h>
15#include <linux/slab.h>
16#include <linux/wait.h>
17#include <linux/cdev.h>
18#include <linux/idr.h>
19#include <linux/fs.h>
20#include <linux/uio.h>
21
22#include <net/net_namespace.h>
23#include <net/rtnetlink.h>
24#include <net/sock.h>
25#include <linux/virtio_net.h>
26#include <linux/skb_array.h>
27
28struct macvtap_dev {
29 struct macvlan_dev vlan;
30 struct tap_dev tap;
31};
32
33/*
34 * Variables for dealing with macvtaps device numbers.
35 */
36static dev_t macvtap_major;
37
38static const void *macvtap_net_namespace(const struct device *d)
39{
40 const struct net_device *dev = to_net_dev(d->parent);
41 return dev_net(dev);
42}
43
44static struct class macvtap_class = {
45 .name = "macvtap",
46 .ns_type = &net_ns_type_operations,
47 .namespace = macvtap_net_namespace,
48};
49static struct cdev macvtap_cdev;
50
51#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
52 NETIF_F_TSO6)
53
54static void macvtap_count_tx_dropped(struct tap_dev *tap)
55{
56 struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
57 struct macvlan_dev *vlan = &vlantap->vlan;
58
59 this_cpu_inc(vlan->pcpu_stats->tx_dropped);
60}
61
62static void macvtap_count_rx_dropped(struct tap_dev *tap)
63{
64 struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
65 struct macvlan_dev *vlan = &vlantap->vlan;
66
67 macvlan_count_rx(vlan, 0, 0, 0);
68}
69
70static void macvtap_update_features(struct tap_dev *tap,
71 netdev_features_t features)
72{
73 struct macvtap_dev *vlantap = container_of(tap, struct macvtap_dev, tap);
74 struct macvlan_dev *vlan = &vlantap->vlan;
75
76 vlan->set_features = features;
77 netdev_update_features(vlan->dev);
78}
79
80static int macvtap_newlink(struct net *src_net, struct net_device *dev,
81 struct nlattr *tb[], struct nlattr *data[],
82 struct netlink_ext_ack *extack)
83{
84 struct macvtap_dev *vlantap = netdev_priv(dev);
85 int err;
86
87 INIT_LIST_HEAD(&vlantap->tap.queue_list);
88
89 /* Since macvlan supports all offloads by default, make
90 * tap support all offloads also.
91 */
92 vlantap->tap.tap_features = TUN_OFFLOADS;
93
94 /* Register callbacks for rx/tx drops accounting and updating
95 * net_device features
96 */
97 vlantap->tap.count_tx_dropped = macvtap_count_tx_dropped;
98 vlantap->tap.count_rx_dropped = macvtap_count_rx_dropped;
99 vlantap->tap.update_features = macvtap_update_features;
100
101 err = netdev_rx_handler_register(dev, tap_handle_frame, &vlantap->tap);
102 if (err)
103 return err;
104
105 /* Don't put anything that may fail after macvlan_common_newlink
106 * because we can't undo what it does.
107 */
108 err = macvlan_common_newlink(src_net, dev, tb, data, extack);
109 if (err) {
110 netdev_rx_handler_unregister(dev);
111 return err;
112 }
113
114 vlantap->tap.dev = vlantap->vlan.dev;
115
116 return 0;
117}
118
119static void macvtap_dellink(struct net_device *dev,
120 struct list_head *head)
121{
122 struct macvtap_dev *vlantap = netdev_priv(dev);
123
124 netdev_rx_handler_unregister(dev);
125 tap_del_queues(&vlantap->tap);
126 macvlan_dellink(dev, head);
127}
128
129static void macvtap_setup(struct net_device *dev)
130{
131 macvlan_common_setup(dev);
132 dev->tx_queue_len = TUN_READQ_SIZE;
133}
134
135static struct net *macvtap_link_net(const struct net_device *dev)
136{
137 return dev_net(macvlan_dev_real_dev(dev));
138}
139
140static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
141 .kind = "macvtap",
142 .setup = macvtap_setup,
143 .newlink = macvtap_newlink,
144 .dellink = macvtap_dellink,
145 .get_link_net = macvtap_link_net,
146 .priv_size = sizeof(struct macvtap_dev),
147};
148
149static int macvtap_device_event(struct notifier_block *unused,
150 unsigned long event, void *ptr)
151{
152 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
153 struct macvtap_dev *vlantap;
154 struct device *classdev;
155 dev_t devt;
156 int err;
157 char tap_name[IFNAMSIZ];
158
159 if (dev->rtnl_link_ops != &macvtap_link_ops)
160 return NOTIFY_DONE;
161
162 snprintf(tap_name, IFNAMSIZ, "tap%d", dev->ifindex);
163 vlantap = netdev_priv(dev);
164
165 switch (event) {
166 case NETDEV_REGISTER:
167 /* Create the device node here after the network device has
168 * been registered but before register_netdevice has
169 * finished running.
170 */
171 err = tap_get_minor(macvtap_major, &vlantap->tap);
172 if (err)
173 return notifier_from_errno(err);
174
175 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
176 classdev = device_create(&macvtap_class, &dev->dev, devt,
177 dev, "%s", tap_name);
178 if (IS_ERR(classdev)) {
179 tap_free_minor(macvtap_major, &vlantap->tap);
180 return notifier_from_errno(PTR_ERR(classdev));
181 }
182 err = sysfs_create_link(&dev->dev.kobj, &classdev->kobj,
183 tap_name);
184 if (err)
185 return notifier_from_errno(err);
186 break;
187 case NETDEV_UNREGISTER:
188 /* vlan->minor == 0 if NETDEV_REGISTER above failed */
189 if (vlantap->tap.minor == 0)
190 break;
191 sysfs_remove_link(&dev->dev.kobj, tap_name);
192 devt = MKDEV(MAJOR(macvtap_major), vlantap->tap.minor);
193 device_destroy(&macvtap_class, devt);
194 tap_free_minor(macvtap_major, &vlantap->tap);
195 break;
196 case NETDEV_CHANGE_TX_QUEUE_LEN:
197 if (tap_queue_resize(&vlantap->tap))
198 return NOTIFY_BAD;
199 break;
200 }
201
202 return NOTIFY_DONE;
203}
204
205static struct notifier_block macvtap_notifier_block __read_mostly = {
206 .notifier_call = macvtap_device_event,
207};
208
209static int __init macvtap_init(void)
210{
211 int err;
212
213 err = tap_create_cdev(&macvtap_cdev, &macvtap_major, "macvtap",
214 THIS_MODULE);
215 if (err)
216 goto out1;
217
218 err = class_register(&macvtap_class);
219 if (err)
220 goto out2;
221
222 err = register_netdevice_notifier(&macvtap_notifier_block);
223 if (err)
224 goto out3;
225
226 err = macvlan_link_register(&macvtap_link_ops);
227 if (err)
228 goto out4;
229
230 return 0;
231
232out4:
233 unregister_netdevice_notifier(&macvtap_notifier_block);
234out3:
235 class_unregister(&macvtap_class);
236out2:
237 tap_destroy_cdev(macvtap_major, &macvtap_cdev);
238out1:
239 return err;
240}
241module_init(macvtap_init);
242
243static void __exit macvtap_exit(void)
244{
245 rtnl_link_unregister(&macvtap_link_ops);
246 unregister_netdevice_notifier(&macvtap_notifier_block);
247 class_unregister(&macvtap_class);
248 tap_destroy_cdev(macvtap_major, &macvtap_cdev);
249}
250module_exit(macvtap_exit);
251
252MODULE_ALIAS_RTNL_LINK("macvtap");
253MODULE_DESCRIPTION("MAC-VLAN based tap driver");
254MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
255MODULE_LICENSE("GPL");
1#include <linux/etherdevice.h>
2#include <linux/if_macvlan.h>
3#include <linux/if_vlan.h>
4#include <linux/interrupt.h>
5#include <linux/nsproxy.h>
6#include <linux/compat.h>
7#include <linux/if_tun.h>
8#include <linux/module.h>
9#include <linux/skbuff.h>
10#include <linux/cache.h>
11#include <linux/sched.h>
12#include <linux/types.h>
13#include <linux/slab.h>
14#include <linux/wait.h>
15#include <linux/cdev.h>
16#include <linux/idr.h>
17#include <linux/fs.h>
18
19#include <net/net_namespace.h>
20#include <net/rtnetlink.h>
21#include <net/sock.h>
22#include <linux/virtio_net.h>
23
24/*
25 * A macvtap queue is the central object of this driver, it connects
26 * an open character device to a macvlan interface. There can be
27 * multiple queues on one interface, which map back to queues
28 * implemented in hardware on the underlying device.
29 *
30 * macvtap_proto is used to allocate queues through the sock allocation
31 * mechanism.
32 *
33 */
34struct macvtap_queue {
35 struct sock sk;
36 struct socket sock;
37 struct socket_wq wq;
38 int vnet_hdr_sz;
39 struct macvlan_dev __rcu *vlan;
40 struct file *file;
41 unsigned int flags;
42 u16 queue_index;
43 bool enabled;
44 struct list_head next;
45};
46
47static struct proto macvtap_proto = {
48 .name = "macvtap",
49 .owner = THIS_MODULE,
50 .obj_size = sizeof (struct macvtap_queue),
51};
52
53/*
54 * Variables for dealing with macvtaps device numbers.
55 */
56static dev_t macvtap_major;
57#define MACVTAP_NUM_DEVS (1U << MINORBITS)
58static DEFINE_MUTEX(minor_lock);
59static DEFINE_IDR(minor_idr);
60
61#define GOODCOPY_LEN 128
62static struct class *macvtap_class;
63static struct cdev macvtap_cdev;
64
65static const struct proto_ops macvtap_socket_ops;
66
67#define TUN_OFFLOADS (NETIF_F_HW_CSUM | NETIF_F_TSO_ECN | NETIF_F_TSO | \
68 NETIF_F_TSO6 | NETIF_F_UFO)
69#define RX_OFFLOADS (NETIF_F_GRO | NETIF_F_LRO)
70#define TAP_FEATURES (NETIF_F_GSO | NETIF_F_SG)
71
72static struct macvlan_dev *macvtap_get_vlan_rcu(const struct net_device *dev)
73{
74 return rcu_dereference(dev->rx_handler_data);
75}
76
77/*
78 * RCU usage:
79 * The macvtap_queue and the macvlan_dev are loosely coupled, the
80 * pointers from one to the other can only be read while rcu_read_lock
81 * or rtnl is held.
82 *
83 * Both the file and the macvlan_dev hold a reference on the macvtap_queue
84 * through sock_hold(&q->sk). When the macvlan_dev goes away first,
85 * q->vlan becomes inaccessible. When the files gets closed,
86 * macvtap_get_queue() fails.
87 *
88 * There may still be references to the struct sock inside of the
89 * queue from outbound SKBs, but these never reference back to the
90 * file or the dev. The data structure is freed through __sk_free
91 * when both our references and any pending SKBs are gone.
92 */
93
94static int macvtap_enable_queue(struct net_device *dev, struct file *file,
95 struct macvtap_queue *q)
96{
97 struct macvlan_dev *vlan = netdev_priv(dev);
98 int err = -EINVAL;
99
100 ASSERT_RTNL();
101
102 if (q->enabled)
103 goto out;
104
105 err = 0;
106 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
107 q->queue_index = vlan->numvtaps;
108 q->enabled = true;
109
110 vlan->numvtaps++;
111out:
112 return err;
113}
114
115static int macvtap_set_queue(struct net_device *dev, struct file *file,
116 struct macvtap_queue *q)
117{
118 struct macvlan_dev *vlan = netdev_priv(dev);
119 int err = -EBUSY;
120
121 rtnl_lock();
122 if (vlan->numqueues == MAX_MACVTAP_QUEUES)
123 goto out;
124
125 err = 0;
126 rcu_assign_pointer(q->vlan, vlan);
127 rcu_assign_pointer(vlan->taps[vlan->numvtaps], q);
128 sock_hold(&q->sk);
129
130 q->file = file;
131 q->queue_index = vlan->numvtaps;
132 q->enabled = true;
133 file->private_data = q;
134 list_add_tail(&q->next, &vlan->queue_list);
135
136 vlan->numvtaps++;
137 vlan->numqueues++;
138
139out:
140 rtnl_unlock();
141 return err;
142}
143
144static int macvtap_disable_queue(struct macvtap_queue *q)
145{
146 struct macvlan_dev *vlan;
147 struct macvtap_queue *nq;
148
149 ASSERT_RTNL();
150 if (!q->enabled)
151 return -EINVAL;
152
153 vlan = rtnl_dereference(q->vlan);
154
155 if (vlan) {
156 int index = q->queue_index;
157 BUG_ON(index >= vlan->numvtaps);
158 nq = rtnl_dereference(vlan->taps[vlan->numvtaps - 1]);
159 nq->queue_index = index;
160
161 rcu_assign_pointer(vlan->taps[index], nq);
162 RCU_INIT_POINTER(vlan->taps[vlan->numvtaps - 1], NULL);
163 q->enabled = false;
164
165 vlan->numvtaps--;
166 }
167
168 return 0;
169}
170
171/*
172 * The file owning the queue got closed, give up both
173 * the reference that the files holds as well as the
174 * one from the macvlan_dev if that still exists.
175 *
176 * Using the spinlock makes sure that we don't get
177 * to the queue again after destroying it.
178 */
179static void macvtap_put_queue(struct macvtap_queue *q)
180{
181 struct macvlan_dev *vlan;
182
183 rtnl_lock();
184 vlan = rtnl_dereference(q->vlan);
185
186 if (vlan) {
187 if (q->enabled)
188 BUG_ON(macvtap_disable_queue(q));
189
190 vlan->numqueues--;
191 RCU_INIT_POINTER(q->vlan, NULL);
192 sock_put(&q->sk);
193 list_del_init(&q->next);
194 }
195
196 rtnl_unlock();
197
198 synchronize_rcu();
199 sock_put(&q->sk);
200}
201
202/*
203 * Select a queue based on the rxq of the device on which this packet
204 * arrived. If the incoming device is not mq, calculate a flow hash
205 * to select a queue. If all fails, find the first available queue.
206 * Cache vlan->numvtaps since it can become zero during the execution
207 * of this function.
208 */
209static struct macvtap_queue *macvtap_get_queue(struct net_device *dev,
210 struct sk_buff *skb)
211{
212 struct macvlan_dev *vlan = netdev_priv(dev);
213 struct macvtap_queue *tap = NULL;
214 /* Access to taps array is protected by rcu, but access to numvtaps
215 * isn't. Below we use it to lookup a queue, but treat it as a hint
216 * and validate that the result isn't NULL - in case we are
217 * racing against queue removal.
218 */
219 int numvtaps = ACCESS_ONCE(vlan->numvtaps);
220 __u32 rxq;
221
222 if (!numvtaps)
223 goto out;
224
225 /* Check if we can use flow to select a queue */
226 rxq = skb_get_hash(skb);
227 if (rxq) {
228 tap = rcu_dereference(vlan->taps[rxq % numvtaps]);
229 goto out;
230 }
231
232 if (likely(skb_rx_queue_recorded(skb))) {
233 rxq = skb_get_rx_queue(skb);
234
235 while (unlikely(rxq >= numvtaps))
236 rxq -= numvtaps;
237
238 tap = rcu_dereference(vlan->taps[rxq]);
239 goto out;
240 }
241
242 tap = rcu_dereference(vlan->taps[0]);
243out:
244 return tap;
245}
246
247/*
248 * The net_device is going away, give up the reference
249 * that it holds on all queues and safely set the pointer
250 * from the queues to NULL.
251 */
252static void macvtap_del_queues(struct net_device *dev)
253{
254 struct macvlan_dev *vlan = netdev_priv(dev);
255 struct macvtap_queue *q, *tmp, *qlist[MAX_MACVTAP_QUEUES];
256 int i, j = 0;
257
258 ASSERT_RTNL();
259 list_for_each_entry_safe(q, tmp, &vlan->queue_list, next) {
260 list_del_init(&q->next);
261 qlist[j++] = q;
262 RCU_INIT_POINTER(q->vlan, NULL);
263 if (q->enabled)
264 vlan->numvtaps--;
265 vlan->numqueues--;
266 }
267 for (i = 0; i < vlan->numvtaps; i++)
268 RCU_INIT_POINTER(vlan->taps[i], NULL);
269 BUG_ON(vlan->numvtaps);
270 BUG_ON(vlan->numqueues);
271 /* guarantee that any future macvtap_set_queue will fail */
272 vlan->numvtaps = MAX_MACVTAP_QUEUES;
273
274 for (--j; j >= 0; j--)
275 sock_put(&qlist[j]->sk);
276}
277
278static rx_handler_result_t macvtap_handle_frame(struct sk_buff **pskb)
279{
280 struct sk_buff *skb = *pskb;
281 struct net_device *dev = skb->dev;
282 struct macvlan_dev *vlan;
283 struct macvtap_queue *q;
284 netdev_features_t features = TAP_FEATURES;
285
286 vlan = macvtap_get_vlan_rcu(dev);
287 if (!vlan)
288 return RX_HANDLER_PASS;
289
290 q = macvtap_get_queue(dev, skb);
291 if (!q)
292 return RX_HANDLER_PASS;
293
294 if (skb_queue_len(&q->sk.sk_receive_queue) >= dev->tx_queue_len)
295 goto drop;
296
297 skb_push(skb, ETH_HLEN);
298
299 /* Apply the forward feature mask so that we perform segmentation
300 * according to users wishes. This only works if VNET_HDR is
301 * enabled.
302 */
303 if (q->flags & IFF_VNET_HDR)
304 features |= vlan->tap_features;
305 if (netif_needs_gso(skb, features)) {
306 struct sk_buff *segs = __skb_gso_segment(skb, features, false);
307
308 if (IS_ERR(segs))
309 goto drop;
310
311 if (!segs) {
312 skb_queue_tail(&q->sk.sk_receive_queue, skb);
313 goto wake_up;
314 }
315
316 kfree_skb(skb);
317 while (segs) {
318 struct sk_buff *nskb = segs->next;
319
320 segs->next = NULL;
321 skb_queue_tail(&q->sk.sk_receive_queue, segs);
322 segs = nskb;
323 }
324 } else {
325 /* If we receive a partial checksum and the tap side
326 * doesn't support checksum offload, compute the checksum.
327 * Note: it doesn't matter which checksum feature to
328 * check, we either support them all or none.
329 */
330 if (skb->ip_summed == CHECKSUM_PARTIAL &&
331 !(features & NETIF_F_ALL_CSUM) &&
332 skb_checksum_help(skb))
333 goto drop;
334 skb_queue_tail(&q->sk.sk_receive_queue, skb);
335 }
336
337wake_up:
338 wake_up_interruptible_poll(sk_sleep(&q->sk), POLLIN | POLLRDNORM | POLLRDBAND);
339 return RX_HANDLER_CONSUMED;
340
341drop:
342 /* Count errors/drops only here, thus don't care about args. */
343 macvlan_count_rx(vlan, 0, 0, 0);
344 kfree_skb(skb);
345 return RX_HANDLER_CONSUMED;
346}
347
348static int macvtap_get_minor(struct macvlan_dev *vlan)
349{
350 int retval = -ENOMEM;
351
352 mutex_lock(&minor_lock);
353 retval = idr_alloc(&minor_idr, vlan, 1, MACVTAP_NUM_DEVS, GFP_KERNEL);
354 if (retval >= 0) {
355 vlan->minor = retval;
356 } else if (retval == -ENOSPC) {
357 printk(KERN_ERR "too many macvtap devices\n");
358 retval = -EINVAL;
359 }
360 mutex_unlock(&minor_lock);
361 return retval < 0 ? retval : 0;
362}
363
364static void macvtap_free_minor(struct macvlan_dev *vlan)
365{
366 mutex_lock(&minor_lock);
367 if (vlan->minor) {
368 idr_remove(&minor_idr, vlan->minor);
369 vlan->minor = 0;
370 }
371 mutex_unlock(&minor_lock);
372}
373
374static struct net_device *dev_get_by_macvtap_minor(int minor)
375{
376 struct net_device *dev = NULL;
377 struct macvlan_dev *vlan;
378
379 mutex_lock(&minor_lock);
380 vlan = idr_find(&minor_idr, minor);
381 if (vlan) {
382 dev = vlan->dev;
383 dev_hold(dev);
384 }
385 mutex_unlock(&minor_lock);
386 return dev;
387}
388
389static int macvtap_newlink(struct net *src_net,
390 struct net_device *dev,
391 struct nlattr *tb[],
392 struct nlattr *data[])
393{
394 struct macvlan_dev *vlan = netdev_priv(dev);
395 int err;
396
397 INIT_LIST_HEAD(&vlan->queue_list);
398
399 /* Since macvlan supports all offloads by default, make
400 * tap support all offloads also.
401 */
402 vlan->tap_features = TUN_OFFLOADS;
403
404 err = netdev_rx_handler_register(dev, macvtap_handle_frame, vlan);
405 if (err)
406 return err;
407
408 /* Don't put anything that may fail after macvlan_common_newlink
409 * because we can't undo what it does.
410 */
411 return macvlan_common_newlink(src_net, dev, tb, data);
412}
413
414static void macvtap_dellink(struct net_device *dev,
415 struct list_head *head)
416{
417 netdev_rx_handler_unregister(dev);
418 macvtap_del_queues(dev);
419 macvlan_dellink(dev, head);
420}
421
422static void macvtap_setup(struct net_device *dev)
423{
424 macvlan_common_setup(dev);
425 dev->tx_queue_len = TUN_READQ_SIZE;
426}
427
428static struct rtnl_link_ops macvtap_link_ops __read_mostly = {
429 .kind = "macvtap",
430 .setup = macvtap_setup,
431 .newlink = macvtap_newlink,
432 .dellink = macvtap_dellink,
433};
434
435
436static void macvtap_sock_write_space(struct sock *sk)
437{
438 wait_queue_head_t *wqueue;
439
440 if (!sock_writeable(sk) ||
441 !test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
442 return;
443
444 wqueue = sk_sleep(sk);
445 if (wqueue && waitqueue_active(wqueue))
446 wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
447}
448
449static void macvtap_sock_destruct(struct sock *sk)
450{
451 skb_queue_purge(&sk->sk_receive_queue);
452}
453
454static int macvtap_open(struct inode *inode, struct file *file)
455{
456 struct net *net = current->nsproxy->net_ns;
457 struct net_device *dev = dev_get_by_macvtap_minor(iminor(inode));
458 struct macvtap_queue *q;
459 int err;
460
461 err = -ENODEV;
462 if (!dev)
463 goto out;
464
465 err = -ENOMEM;
466 q = (struct macvtap_queue *)sk_alloc(net, AF_UNSPEC, GFP_KERNEL,
467 &macvtap_proto);
468 if (!q)
469 goto out;
470
471 RCU_INIT_POINTER(q->sock.wq, &q->wq);
472 init_waitqueue_head(&q->wq.wait);
473 q->sock.type = SOCK_RAW;
474 q->sock.state = SS_CONNECTED;
475 q->sock.file = file;
476 q->sock.ops = &macvtap_socket_ops;
477 sock_init_data(&q->sock, &q->sk);
478 q->sk.sk_write_space = macvtap_sock_write_space;
479 q->sk.sk_destruct = macvtap_sock_destruct;
480 q->flags = IFF_VNET_HDR | IFF_NO_PI | IFF_TAP;
481 q->vnet_hdr_sz = sizeof(struct virtio_net_hdr);
482
483 /*
484 * so far only KVM virtio_net uses macvtap, enable zero copy between
485 * guest kernel and host kernel when lower device supports zerocopy
486 *
487 * The macvlan supports zerocopy iff the lower device supports zero
488 * copy so we don't have to look at the lower device directly.
489 */
490 if ((dev->features & NETIF_F_HIGHDMA) && (dev->features & NETIF_F_SG))
491 sock_set_flag(&q->sk, SOCK_ZEROCOPY);
492
493 err = macvtap_set_queue(dev, file, q);
494 if (err)
495 sock_put(&q->sk);
496
497out:
498 if (dev)
499 dev_put(dev);
500
501 return err;
502}
503
504static int macvtap_release(struct inode *inode, struct file *file)
505{
506 struct macvtap_queue *q = file->private_data;
507 macvtap_put_queue(q);
508 return 0;
509}
510
511static unsigned int macvtap_poll(struct file *file, poll_table * wait)
512{
513 struct macvtap_queue *q = file->private_data;
514 unsigned int mask = POLLERR;
515
516 if (!q)
517 goto out;
518
519 mask = 0;
520 poll_wait(file, &q->wq.wait, wait);
521
522 if (!skb_queue_empty(&q->sk.sk_receive_queue))
523 mask |= POLLIN | POLLRDNORM;
524
525 if (sock_writeable(&q->sk) ||
526 (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &q->sock.flags) &&
527 sock_writeable(&q->sk)))
528 mask |= POLLOUT | POLLWRNORM;
529
530out:
531 return mask;
532}
533
534static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
535 size_t len, size_t linear,
536 int noblock, int *err)
537{
538 struct sk_buff *skb;
539
540 /* Under a page? Don't bother with paged skb. */
541 if (prepad + len < PAGE_SIZE || !linear)
542 linear = len;
543
544 skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
545 err, 0);
546 if (!skb)
547 return NULL;
548
549 skb_reserve(skb, prepad);
550 skb_put(skb, linear);
551 skb->data_len = len - linear;
552 skb->len += len - linear;
553
554 return skb;
555}
556
557/*
558 * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
559 * be shared with the tun/tap driver.
560 */
561static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
562 struct virtio_net_hdr *vnet_hdr)
563{
564 unsigned short gso_type = 0;
565 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
566 switch (vnet_hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
567 case VIRTIO_NET_HDR_GSO_TCPV4:
568 gso_type = SKB_GSO_TCPV4;
569 break;
570 case VIRTIO_NET_HDR_GSO_TCPV6:
571 gso_type = SKB_GSO_TCPV6;
572 break;
573 case VIRTIO_NET_HDR_GSO_UDP:
574 gso_type = SKB_GSO_UDP;
575 break;
576 default:
577 return -EINVAL;
578 }
579
580 if (vnet_hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
581 gso_type |= SKB_GSO_TCP_ECN;
582
583 if (vnet_hdr->gso_size == 0)
584 return -EINVAL;
585 }
586
587 if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
588 if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
589 vnet_hdr->csum_offset))
590 return -EINVAL;
591 }
592
593 if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
594 skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
595 skb_shinfo(skb)->gso_type = gso_type;
596
597 /* Header must be checked, and gso_segs computed. */
598 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
599 skb_shinfo(skb)->gso_segs = 0;
600 }
601 return 0;
602}
603
604static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
605 struct virtio_net_hdr *vnet_hdr)
606{
607 memset(vnet_hdr, 0, sizeof(*vnet_hdr));
608
609 if (skb_is_gso(skb)) {
610 struct skb_shared_info *sinfo = skb_shinfo(skb);
611
612 /* This is a hint as to how much should be linear. */
613 vnet_hdr->hdr_len = skb_headlen(skb);
614 vnet_hdr->gso_size = sinfo->gso_size;
615 if (sinfo->gso_type & SKB_GSO_TCPV4)
616 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
617 else if (sinfo->gso_type & SKB_GSO_TCPV6)
618 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
619 else if (sinfo->gso_type & SKB_GSO_UDP)
620 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
621 else
622 BUG();
623 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
624 vnet_hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
625 } else
626 vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
627
628 if (skb->ip_summed == CHECKSUM_PARTIAL) {
629 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
630 vnet_hdr->csum_start = skb_checksum_start_offset(skb);
631 vnet_hdr->csum_offset = skb->csum_offset;
632 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
633 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
634 } /* else everything is zero */
635}
636
637/* Get packet from user space buffer */
638static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
639 const struct iovec *iv, unsigned long total_len,
640 size_t count, int noblock)
641{
642 int good_linear = SKB_MAX_HEAD(NET_IP_ALIGN);
643 struct sk_buff *skb;
644 struct macvlan_dev *vlan;
645 unsigned long len = total_len;
646 int err;
647 struct virtio_net_hdr vnet_hdr = { 0 };
648 int vnet_hdr_len = 0;
649 int copylen = 0;
650 bool zerocopy = false;
651 size_t linear;
652
653 if (q->flags & IFF_VNET_HDR) {
654 vnet_hdr_len = q->vnet_hdr_sz;
655
656 err = -EINVAL;
657 if (len < vnet_hdr_len)
658 goto err;
659 len -= vnet_hdr_len;
660
661 err = memcpy_fromiovecend((void *)&vnet_hdr, iv, 0,
662 sizeof(vnet_hdr));
663 if (err < 0)
664 goto err;
665 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
666 vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
667 vnet_hdr.hdr_len)
668 vnet_hdr.hdr_len = vnet_hdr.csum_start +
669 vnet_hdr.csum_offset + 2;
670 err = -EINVAL;
671 if (vnet_hdr.hdr_len > len)
672 goto err;
673 }
674
675 err = -EINVAL;
676 if (unlikely(len < ETH_HLEN))
677 goto err;
678
679 err = -EMSGSIZE;
680 if (unlikely(count > UIO_MAXIOV))
681 goto err;
682
683 if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
684 copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
685 if (copylen > good_linear)
686 copylen = good_linear;
687 linear = copylen;
688 if (iov_pages(iv, vnet_hdr_len + copylen, count)
689 <= MAX_SKB_FRAGS)
690 zerocopy = true;
691 }
692
693 if (!zerocopy) {
694 copylen = len;
695 if (vnet_hdr.hdr_len > good_linear)
696 linear = good_linear;
697 else
698 linear = vnet_hdr.hdr_len;
699 }
700
701 skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
702 linear, noblock, &err);
703 if (!skb)
704 goto err;
705
706 if (zerocopy)
707 err = zerocopy_sg_from_iovec(skb, iv, vnet_hdr_len, count);
708 else {
709 err = skb_copy_datagram_from_iovec(skb, 0, iv, vnet_hdr_len,
710 len);
711 if (!err && m && m->msg_control) {
712 struct ubuf_info *uarg = m->msg_control;
713 uarg->callback(uarg, false);
714 }
715 }
716
717 if (err)
718 goto err_kfree;
719
720 skb_set_network_header(skb, ETH_HLEN);
721 skb_reset_mac_header(skb);
722 skb->protocol = eth_hdr(skb)->h_proto;
723
724 if (vnet_hdr_len) {
725 err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
726 if (err)
727 goto err_kfree;
728 }
729
730 skb_probe_transport_header(skb, ETH_HLEN);
731
732 rcu_read_lock();
733 vlan = rcu_dereference(q->vlan);
734 /* copy skb_ubuf_info for callback when skb has no error */
735 if (zerocopy) {
736 skb_shinfo(skb)->destructor_arg = m->msg_control;
737 skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
738 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
739 }
740 if (vlan) {
741 skb->dev = vlan->dev;
742 dev_queue_xmit(skb);
743 } else {
744 kfree_skb(skb);
745 }
746 rcu_read_unlock();
747
748 return total_len;
749
750err_kfree:
751 kfree_skb(skb);
752
753err:
754 rcu_read_lock();
755 vlan = rcu_dereference(q->vlan);
756 if (vlan)
757 this_cpu_inc(vlan->pcpu_stats->tx_dropped);
758 rcu_read_unlock();
759
760 return err;
761}
762
763static ssize_t macvtap_aio_write(struct kiocb *iocb, const struct iovec *iv,
764 unsigned long count, loff_t pos)
765{
766 struct file *file = iocb->ki_filp;
767 ssize_t result = -ENOLINK;
768 struct macvtap_queue *q = file->private_data;
769
770 result = macvtap_get_user(q, NULL, iv, iov_length(iv, count), count,
771 file->f_flags & O_NONBLOCK);
772 return result;
773}
774
775/* Put packet to the user space buffer */
776static ssize_t macvtap_put_user(struct macvtap_queue *q,
777 const struct sk_buff *skb,
778 const struct iovec *iv, int len)
779{
780 int ret;
781 int vnet_hdr_len = 0;
782 int vlan_offset = 0;
783 int copied, total;
784
785 if (q->flags & IFF_VNET_HDR) {
786 struct virtio_net_hdr vnet_hdr;
787 vnet_hdr_len = q->vnet_hdr_sz;
788 if ((len -= vnet_hdr_len) < 0)
789 return -EINVAL;
790
791 macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
792
793 if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
794 return -EFAULT;
795 }
796 total = copied = vnet_hdr_len;
797 total += skb->len;
798
799 if (!vlan_tx_tag_present(skb))
800 len = min_t(int, skb->len, len);
801 else {
802 int copy;
803 struct {
804 __be16 h_vlan_proto;
805 __be16 h_vlan_TCI;
806 } veth;
807 veth.h_vlan_proto = skb->vlan_proto;
808 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
809
810 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
811 len = min_t(int, skb->len + VLAN_HLEN, len);
812 total += VLAN_HLEN;
813
814 copy = min_t(int, vlan_offset, len);
815 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
816 len -= copy;
817 copied += copy;
818 if (ret || !len)
819 goto done;
820
821 copy = min_t(int, sizeof(veth), len);
822 ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
823 len -= copy;
824 copied += copy;
825 if (ret || !len)
826 goto done;
827 }
828
829 ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
830
831done:
832 return ret ? ret : total;
833}
834
835static ssize_t macvtap_do_read(struct macvtap_queue *q,
836 const struct iovec *iv, unsigned long len,
837 int noblock)
838{
839 DEFINE_WAIT(wait);
840 struct sk_buff *skb;
841 ssize_t ret = 0;
842
843 while (len) {
844 if (!noblock)
845 prepare_to_wait(sk_sleep(&q->sk), &wait,
846 TASK_INTERRUPTIBLE);
847
848 /* Read frames from the queue */
849 skb = skb_dequeue(&q->sk.sk_receive_queue);
850 if (!skb) {
851 if (noblock) {
852 ret = -EAGAIN;
853 break;
854 }
855 if (signal_pending(current)) {
856 ret = -ERESTARTSYS;
857 break;
858 }
859 /* Nothing to read, let's sleep */
860 schedule();
861 continue;
862 }
863 ret = macvtap_put_user(q, skb, iv, len);
864 kfree_skb(skb);
865 break;
866 }
867
868 if (!noblock)
869 finish_wait(sk_sleep(&q->sk), &wait);
870 return ret;
871}
872
873static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
874 unsigned long count, loff_t pos)
875{
876 struct file *file = iocb->ki_filp;
877 struct macvtap_queue *q = file->private_data;
878 ssize_t len, ret = 0;
879
880 len = iov_length(iv, count);
881 if (len < 0) {
882 ret = -EINVAL;
883 goto out;
884 }
885
886 ret = macvtap_do_read(q, iv, len, file->f_flags & O_NONBLOCK);
887 ret = min_t(ssize_t, ret, len);
888 if (ret > 0)
889 iocb->ki_pos = ret;
890out:
891 return ret;
892}
893
894static struct macvlan_dev *macvtap_get_vlan(struct macvtap_queue *q)
895{
896 struct macvlan_dev *vlan;
897
898 ASSERT_RTNL();
899 vlan = rtnl_dereference(q->vlan);
900 if (vlan)
901 dev_hold(vlan->dev);
902
903 return vlan;
904}
905
906static void macvtap_put_vlan(struct macvlan_dev *vlan)
907{
908 dev_put(vlan->dev);
909}
910
911static int macvtap_ioctl_set_queue(struct file *file, unsigned int flags)
912{
913 struct macvtap_queue *q = file->private_data;
914 struct macvlan_dev *vlan;
915 int ret;
916
917 vlan = macvtap_get_vlan(q);
918 if (!vlan)
919 return -EINVAL;
920
921 if (flags & IFF_ATTACH_QUEUE)
922 ret = macvtap_enable_queue(vlan->dev, file, q);
923 else if (flags & IFF_DETACH_QUEUE)
924 ret = macvtap_disable_queue(q);
925 else
926 ret = -EINVAL;
927
928 macvtap_put_vlan(vlan);
929 return ret;
930}
931
932static int set_offload(struct macvtap_queue *q, unsigned long arg)
933{
934 struct macvlan_dev *vlan;
935 netdev_features_t features;
936 netdev_features_t feature_mask = 0;
937
938 vlan = rtnl_dereference(q->vlan);
939 if (!vlan)
940 return -ENOLINK;
941
942 features = vlan->dev->features;
943
944 if (arg & TUN_F_CSUM) {
945 feature_mask = NETIF_F_HW_CSUM;
946
947 if (arg & (TUN_F_TSO4 | TUN_F_TSO6)) {
948 if (arg & TUN_F_TSO_ECN)
949 feature_mask |= NETIF_F_TSO_ECN;
950 if (arg & TUN_F_TSO4)
951 feature_mask |= NETIF_F_TSO;
952 if (arg & TUN_F_TSO6)
953 feature_mask |= NETIF_F_TSO6;
954 }
955
956 if (arg & TUN_F_UFO)
957 feature_mask |= NETIF_F_UFO;
958 }
959
960 /* tun/tap driver inverts the usage for TSO offloads, where
961 * setting the TSO bit means that the userspace wants to
962 * accept TSO frames and turning it off means that user space
963 * does not support TSO.
964 * For macvtap, we have to invert it to mean the same thing.
965 * When user space turns off TSO, we turn off GSO/LRO so that
966 * user-space will not receive TSO frames.
967 */
968 if (feature_mask & (NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_UFO))
969 features |= RX_OFFLOADS;
970 else
971 features &= ~RX_OFFLOADS;
972
973 /* tap_features are the same as features on tun/tap and
974 * reflect user expectations.
975 */
976 vlan->tap_features = feature_mask;
977 vlan->set_features = features;
978 netdev_update_features(vlan->dev);
979
980 return 0;
981}
982
983/*
984 * provide compatibility with generic tun/tap interface
985 */
986static long macvtap_ioctl(struct file *file, unsigned int cmd,
987 unsigned long arg)
988{
989 struct macvtap_queue *q = file->private_data;
990 struct macvlan_dev *vlan;
991 void __user *argp = (void __user *)arg;
992 struct ifreq __user *ifr = argp;
993 unsigned int __user *up = argp;
994 unsigned int u;
995 int __user *sp = argp;
996 int s;
997 int ret;
998
999 switch (cmd) {
1000 case TUNSETIFF:
1001 /* ignore the name, just look at flags */
1002 if (get_user(u, &ifr->ifr_flags))
1003 return -EFAULT;
1004
1005 ret = 0;
1006 if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
1007 (IFF_NO_PI | IFF_TAP))
1008 ret = -EINVAL;
1009 else
1010 q->flags = u;
1011
1012 return ret;
1013
1014 case TUNGETIFF:
1015 rtnl_lock();
1016 vlan = macvtap_get_vlan(q);
1017 if (!vlan) {
1018 rtnl_unlock();
1019 return -ENOLINK;
1020 }
1021
1022 ret = 0;
1023 if (copy_to_user(&ifr->ifr_name, vlan->dev->name, IFNAMSIZ) ||
1024 put_user(q->flags, &ifr->ifr_flags))
1025 ret = -EFAULT;
1026 macvtap_put_vlan(vlan);
1027 rtnl_unlock();
1028 return ret;
1029
1030 case TUNSETQUEUE:
1031 if (get_user(u, &ifr->ifr_flags))
1032 return -EFAULT;
1033 rtnl_lock();
1034 ret = macvtap_ioctl_set_queue(file, u);
1035 rtnl_unlock();
1036 return ret;
1037
1038 case TUNGETFEATURES:
1039 if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |
1040 IFF_MULTI_QUEUE, up))
1041 return -EFAULT;
1042 return 0;
1043
1044 case TUNSETSNDBUF:
1045 if (get_user(u, up))
1046 return -EFAULT;
1047
1048 q->sk.sk_sndbuf = u;
1049 return 0;
1050
1051 case TUNGETVNETHDRSZ:
1052 s = q->vnet_hdr_sz;
1053 if (put_user(s, sp))
1054 return -EFAULT;
1055 return 0;
1056
1057 case TUNSETVNETHDRSZ:
1058 if (get_user(s, sp))
1059 return -EFAULT;
1060 if (s < (int)sizeof(struct virtio_net_hdr))
1061 return -EINVAL;
1062
1063 q->vnet_hdr_sz = s;
1064 return 0;
1065
1066 case TUNSETOFFLOAD:
1067 /* let the user check for future flags */
1068 if (arg & ~(TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6 |
1069 TUN_F_TSO_ECN | TUN_F_UFO))
1070 return -EINVAL;
1071
1072 rtnl_lock();
1073 ret = set_offload(q, arg);
1074 rtnl_unlock();
1075 return ret;
1076
1077 default:
1078 return -EINVAL;
1079 }
1080}
1081
1082#ifdef CONFIG_COMPAT
1083static long macvtap_compat_ioctl(struct file *file, unsigned int cmd,
1084 unsigned long arg)
1085{
1086 return macvtap_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
1087}
1088#endif
1089
1090static const struct file_operations macvtap_fops = {
1091 .owner = THIS_MODULE,
1092 .open = macvtap_open,
1093 .release = macvtap_release,
1094 .aio_read = macvtap_aio_read,
1095 .aio_write = macvtap_aio_write,
1096 .poll = macvtap_poll,
1097 .llseek = no_llseek,
1098 .unlocked_ioctl = macvtap_ioctl,
1099#ifdef CONFIG_COMPAT
1100 .compat_ioctl = macvtap_compat_ioctl,
1101#endif
1102};
1103
1104static int macvtap_sendmsg(struct kiocb *iocb, struct socket *sock,
1105 struct msghdr *m, size_t total_len)
1106{
1107 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1108 return macvtap_get_user(q, m, m->msg_iov, total_len, m->msg_iovlen,
1109 m->msg_flags & MSG_DONTWAIT);
1110}
1111
1112static int macvtap_recvmsg(struct kiocb *iocb, struct socket *sock,
1113 struct msghdr *m, size_t total_len,
1114 int flags)
1115{
1116 struct macvtap_queue *q = container_of(sock, struct macvtap_queue, sock);
1117 int ret;
1118 if (flags & ~(MSG_DONTWAIT|MSG_TRUNC))
1119 return -EINVAL;
1120 ret = macvtap_do_read(q, m->msg_iov, total_len,
1121 flags & MSG_DONTWAIT);
1122 if (ret > total_len) {
1123 m->msg_flags |= MSG_TRUNC;
1124 ret = flags & MSG_TRUNC ? ret : total_len;
1125 }
1126 return ret;
1127}
1128
1129/* Ops structure to mimic raw sockets with tun */
1130static const struct proto_ops macvtap_socket_ops = {
1131 .sendmsg = macvtap_sendmsg,
1132 .recvmsg = macvtap_recvmsg,
1133};
1134
1135/* Get an underlying socket object from tun file. Returns error unless file is
1136 * attached to a device. The returned object works like a packet socket, it
1137 * can be used for sock_sendmsg/sock_recvmsg. The caller is responsible for
1138 * holding a reference to the file for as long as the socket is in use. */
1139struct socket *macvtap_get_socket(struct file *file)
1140{
1141 struct macvtap_queue *q;
1142 if (file->f_op != &macvtap_fops)
1143 return ERR_PTR(-EINVAL);
1144 q = file->private_data;
1145 if (!q)
1146 return ERR_PTR(-EBADFD);
1147 return &q->sock;
1148}
1149EXPORT_SYMBOL_GPL(macvtap_get_socket);
1150
1151static int macvtap_device_event(struct notifier_block *unused,
1152 unsigned long event, void *ptr)
1153{
1154 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1155 struct macvlan_dev *vlan;
1156 struct device *classdev;
1157 dev_t devt;
1158 int err;
1159
1160 if (dev->rtnl_link_ops != &macvtap_link_ops)
1161 return NOTIFY_DONE;
1162
1163 vlan = netdev_priv(dev);
1164
1165 switch (event) {
1166 case NETDEV_REGISTER:
1167 /* Create the device node here after the network device has
1168 * been registered but before register_netdevice has
1169 * finished running.
1170 */
1171 err = macvtap_get_minor(vlan);
1172 if (err)
1173 return notifier_from_errno(err);
1174
1175 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1176 classdev = device_create(macvtap_class, &dev->dev, devt,
1177 dev, "tap%d", dev->ifindex);
1178 if (IS_ERR(classdev)) {
1179 macvtap_free_minor(vlan);
1180 return notifier_from_errno(PTR_ERR(classdev));
1181 }
1182 break;
1183 case NETDEV_UNREGISTER:
1184 devt = MKDEV(MAJOR(macvtap_major), vlan->minor);
1185 device_destroy(macvtap_class, devt);
1186 macvtap_free_minor(vlan);
1187 break;
1188 }
1189
1190 return NOTIFY_DONE;
1191}
1192
1193static struct notifier_block macvtap_notifier_block __read_mostly = {
1194 .notifier_call = macvtap_device_event,
1195};
1196
1197static int macvtap_init(void)
1198{
1199 int err;
1200
1201 err = alloc_chrdev_region(&macvtap_major, 0,
1202 MACVTAP_NUM_DEVS, "macvtap");
1203 if (err)
1204 goto out1;
1205
1206 cdev_init(&macvtap_cdev, &macvtap_fops);
1207 err = cdev_add(&macvtap_cdev, macvtap_major, MACVTAP_NUM_DEVS);
1208 if (err)
1209 goto out2;
1210
1211 macvtap_class = class_create(THIS_MODULE, "macvtap");
1212 if (IS_ERR(macvtap_class)) {
1213 err = PTR_ERR(macvtap_class);
1214 goto out3;
1215 }
1216
1217 err = register_netdevice_notifier(&macvtap_notifier_block);
1218 if (err)
1219 goto out4;
1220
1221 err = macvlan_link_register(&macvtap_link_ops);
1222 if (err)
1223 goto out5;
1224
1225 return 0;
1226
1227out5:
1228 unregister_netdevice_notifier(&macvtap_notifier_block);
1229out4:
1230 class_unregister(macvtap_class);
1231out3:
1232 cdev_del(&macvtap_cdev);
1233out2:
1234 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1235out1:
1236 return err;
1237}
1238module_init(macvtap_init);
1239
1240static void macvtap_exit(void)
1241{
1242 rtnl_link_unregister(&macvtap_link_ops);
1243 unregister_netdevice_notifier(&macvtap_notifier_block);
1244 class_unregister(macvtap_class);
1245 cdev_del(&macvtap_cdev);
1246 unregister_chrdev_region(macvtap_major, MACVTAP_NUM_DEVS);
1247}
1248module_exit(macvtap_exit);
1249
1250MODULE_ALIAS_RTNL_LINK("macvtap");
1251MODULE_AUTHOR("Arnd Bergmann <arnd@arndb.de>");
1252MODULE_LICENSE("GPL");